U.S. patent application number 10/127356 was filed with the patent office on 2002-11-28 for drill bit pointing and dirt removal apparatus and method.
Invention is credited to Katayama, Ichiro.
Application Number | 20020174989 10/127356 |
Document ID | / |
Family ID | 18972539 |
Filed Date | 2002-11-28 |
United States Patent
Application |
20020174989 |
Kind Code |
A1 |
Katayama, Ichiro |
November 28, 2002 |
Drill bit pointing and dirt removal apparatus and method
Abstract
An apparatus for pointing twist drill bits includes a processing
unit which has a rotary index plate on which are mounted a
plurality, e.g., five, of drill bit holders which are
circumferentially spaced apart at equal, e.g., 72-degree intervals,
and a loading unit which has located adjacent to the index plate a
rotary pedestal on which are mounted an equal number of transfer
arms. Located around the periphery of the processing unit and
loading unit are a plurality of processing stations and loading
unit operation stations, respectively. Under computer control, the
index plate and pedestal are periodically rotated
non-simultaneously in opposite directions and stopped for
predetermined time periods during which sensors and actuators cause
drill bits to be loaded from a container located at an input/output
station onto a loading unit arm, cleaned, transferred to a drill
bit holder, sequentially processed at processing stations,
including a point grinding station, transferred back to a loading
unit arm, discharged to a defectives container if defective, have a
collar ring adjusted, and returned to the input/output station for
discharge to a transport container. Prior to and after a grinding
process, each drill bit is cleaned by a dirt removal apparatus
which uses a plastically deformable body, preferably a toroidal
roller which is pivoted into contact with a drill bit point,
causing the point to pierce the body and transfer dirt thereto, the
body is then pivoted away from the point with dirt adhered to the
body.
Inventors: |
Katayama, Ichiro; (Nagaoka
City, JP) |
Correspondence
Address: |
William L. Chapin
Law Offices of William L. Chapin
16791 Sea Witch Lane
Huntington Beach
CA
92649
US
|
Family ID: |
18972539 |
Appl. No.: |
10/127356 |
Filed: |
April 19, 2002 |
Current U.S.
Class: |
166/358 ; 15/352;
408/25; 408/45 |
Current CPC
Class: |
Y10T 408/35 20150115;
B24B 55/06 20130101; B24B 3/245 20130101; B24B 19/04 20130101; Y10T
408/381 20150115 |
Class at
Publication: |
166/358 ; 408/45;
408/25; 15/352 |
International
Class: |
B25F 001/00; B27C
003/00; B23B 051/08; A47L 009/20; E21B 007/12; E21B 033/038; E21B
033/064 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 20, 2001 |
JP |
2001-122896 |
Claims
What is claimed is:
1. An apparatus for processing twist drill bits comprising; a. a
processing unit comprising; (i) a support structure, (ii) an index
plate having mounted thereon at least one drill bit holder for
holding a drill bit, (iii) at least a first processing station for
performing a first processing operation on a drill bit held in said
holder, said first processing station being located adjacent to
said index plate at a first index location, (iv) means for movably
supporting said index plate by said support structure to thereby
move said drill bit holder between said first index location and a
load/unload index location adjacent to said index plate and spaced
apart from said first index location, and a. loading means located
at said load/unload index location for cyclically loading and
unloading a drill bit onto and off of said drill bit holder.
2. The apparatus of claim 1 wherein said first processing station
is further defined as including thereat a pointing processing unit
for machining a surface of a drill bit.
3. The apparatus of claim 2 wherein said pointing processing unit
is further defined as including a machining mechanism for machining
the front cutting portion including the tip of a drill bit.
4. The apparatus of claim 2 further including a second processing
station located adjacent to said index plate at a second index
location spaced apart from said first index location, at which is
located a dirt removal processing apparatus for removing dirt from
a drill bit held in said holder.
5. The apparatus of claim 4 wherein said dirt removal apparatus is
further defined as including a plastically deformable body made of
a material which has a tacky surface to which dirt readily adheres,
said deformable body being movably supported by an actuator
mechanism effective in cyclically causing relative approaching
motion between said body and the tip of a drill bit to thereby
cause said tip to pierce said body, and relative retracting motion
to retract said body from said tip after said piercing contact.
6. The apparatus of claim 4 further including a third processing
station located adjacent to said index plate at a third location
spaced apart from said second index location, at which is located a
tip position set-up processing apparatus, said apparatus including
sensor means for sensing the position of said drill bit in said
holder, and actuator means responsive to control signals generated
by said sensor means in moving said drill bit to predetermined
spatial coordinate locations relative to said index plate.
7. The apparatus of claim 6 wherein said tip position set-up
processing unit is further defined as including a tip position
adjustment mechanism for adjusting the tip of said drill bit to a
predetermined spatial coordinate position.
8. The apparatus of claim 6 wherein said tip position set-up
processing unit is further defined as including a center adjustment
mechanism for adjusting the center of said bit to a predetermined
spatial coordinate position.
9. The apparatus of claim 6 wherein said tip position set-up
processing unit is further defined as including a phase adjustment
mechanism for adjusting the rotation angle or phase of said drill
bit.
10. The apparatus of claim 6 further including a fourth processing
station located adjacent to said index plate at a fourth index
location spaced apart from said third index location, at which is
located an inspection processing unit for inspecting a drill bit
processed at said first, pointing processing station.
11. The apparatus of claim 3 wherein said loading means for
cyclically loading and unloading said drill bits from a said drill
bit holder is further defined as comprising a loading unit located
adjacent to said index plate of said processing unit.
12. The apparatus of claim 11 wherein said loading unit is further
defined as comprising; a. a support structure, b. a movable
pedestal having mounted thereon at least one drill bit transfer arm
for holding and transferring an individual drill bit, c. at least a
first operation station for performing a first operation on a drill
bit held by said transfer arm, said first operation station being
located adjacent to said pedestal at a first pedestal index
location, d. input/output transfer means located at said first
pedestal index location for transferring a drill bit from a
transport container onto said transfer arm and off of said transfer
arm to a transport container, e. means for movably supporting said
pedestal by said support structure to thereby move said transfer
arm between said first pedestal index location and a load/unload
station spaced apart from said first index location and adjacent to
said load/unload index location of said processing unit, and f.
load/unload transfer means located at said load/unload index
location for transferring a drill bit from said transfer arm to
said drill bit holder, and from said drill bit holder to said
transfer arm.
13. The apparatus of claim 12 further including a second pedestal
index location, at which is located a dirt removal processing
station.
14. The apparatus of claim 13 further including a third operation
station located at a third pedestal index location, said third
operation station having thereat a rejects receptacle for receiving
defective drill bits.
15. The apparatus of claim 14 further including a fourth operation
station located at a fourth pedestal index location, said fourth
operation station having thereat a collar ring adjustment mechanism
for adjusting the collar ring on a drill bit to be spaced a
predetermined distance from the tip of said drill bit.
16. An apparatus for processing twist drill bits comprising; a. a
drill bit processing unit comprising; (i) a support structure, (ii)
an index plate rotatably mounted on said support structure, said
index plate having mounted thereon a plurality of drill bit holders
located on a circle and spaced circumferentially apart from one
another at equal central angles, each drill bit holder being able
to hold therein an individual drill bit, (iii) a plurality of
processing unit stations spaced apart from said index plate for
performing various processing operations on drill bits in said
drill bit holders, each of said processing stations being located
at an index location located on a circle and spaced
circumferentially apart from one another at equal central angles,
said processing unit stations including a loading/unloading station
for loading an unprocessed drill bit onto a drill bit holder and
unloading a processed drill bit from said holder, and at least, a
first processing station for performing a process on said drill
bit, and (iv) means for rotating said index plate to thereby
position an individual drill bit holder at a particular one of said
plurality of processing unit stations at said index locations, a. a
drill bit loading unit comprising, (i) a support structure, (ii) a
rotary pedestal rotatably mounted on said support structure, said
rotary pedestal having mounted thereon a plurality of drill bit
transfer arms located on a circle and spaced circumferentially
apart from one another at equal angles, each transfer arm being so
constructed as to be able to pick up a drill bit from a location
exterior to said rotary pedestal, hold said drill bit at a
predetermined orientation, and transfer said drill bit to a
location exterior to said rotary pedestal, (iii) a plurality of
operation stations for performing various operations on individual
ones of said drill bits held by said transfer arms, each of said
operation stations being located at a rotary pedestal index
location located on a circle and spaced circumferentially apart
from one another at equal central angles, said operation stations
including an input/output station for loading onto an empty
transfer arm a drill bit to transfer to said processing unit and
for unloading from a transfer arm a drill bit which has been
processed by said processing unit, and a load/unload operation
station coextensive with said loading/unloading station of said
processing unit for transferring a drill bit from a transfer arm on
said rotary pedestal to a drill bit holder on said processing unit
index plate, and from a drill bit holder to said transfer arm, and
(iv) means for rotating said rotary pedestal synchronously with
rotation of said index plate, thereby enabling synchronous transfer
of drill bits between said rotary pedestal and said index
plate.
17. The apparatus of claim 16 wherein said first active processing
station is further defined as including thereat a pointing
processing unit for machining a surface of a drill bit.
18. The apparatus of claim 17 further including between said
loading/unloading index location and said index location of said
pointing processing unit a tip position set-up processing
apparatus, said apparatus including sensor means for sensing the
position of said drill bit in said holder, and actuator means
responsive to control signals generated by said sensor means in
moving said drill bit to predetermined spatial coordinate locations
relative to said index plate.
19. The apparatus of claim 18 wherein said tip position set-up
processing unit is further defined as including a tip position
adjustment mechanism for adjusting the tip of said drill bit to a
predetermined spatial coordinate position.
20. The apparatus of claim 18 wherein said tip position set-up
processing unit is further defined as including a center adjustment
mechanism for adjusting the center of said bit to a predetermined
spatial coordinate position.
21. The apparatus of claim 18 wherein said tip position set-up
processing unit is further defined as including a phase adjustment
mechanism for adjusting the rotation angle or phase of said drill
bit.
22. The apparatus of claim 18 further including a post-grind dirt
removal apparatus for removing dirt from a drill bit held in said
holder.
23. The apparatus of claim 22 wherein said dirt removal apparatus
is further defined as including a plastically deformable body made
of a material which has a tacky surface to which dirt readily
adheres, said deformable body being movably supported by an
actuator mechanism effective in cyclically causing relative
approaching motion between said body and the tip of a drill bit to
thereby cause said tip to pierce said body, and relative retracting
motion to retract said body from said tip after said piercing
contact.
24. The apparatus of claim 18 further including a fourth processing
station located adjacent to said index plate at a fourth index
location spaced apart from said third index location, at which is
located an inspection processing unit for inspecting a drill bit
processed at said first, pointing processing station.
25. The apparatus of claim 16 wherein said drill bit loading unit
is further defined as having at a second rotary pedestal index
locating a dirt removal processing station.
26. The apparatus of claim 23 further including a third operation
station located at a third pedestal index location, said third
operation station having thereat a rejects receptacle for receiving
defective drill bits.
27. The apparatus of claim 26 further including a fourth operation
station located at a fourth pedestal index location, said fourth
operation station having thereat a collar ring adjustment mechanism
for adjusting the collar ring on a drill bit to be spaced a
predetermined distance from the tip of said drill bit.
28. The apparatus of claim 16 wherein the number of said drill bit
holders on said index plate of said processing unit equals the
number of arms on said rotary pedestal of said loading unit.
29. The apparatus of claim 28 wherein each of said arms lies in a
plane perpendicular to said rotary pedestal and containing a radius
of said rotary pedestal.
30. The apparatus of claim 28 wherein each of said drill bit
holders lies in a plane which is perpendicular to said index plate
and obliquely angled with respect to a radius of said index
plate.
31. The apparatus of claim 30 wherein the longitudinal axis of said
drill bit in said drill bit holder is obliquely angled with respect
to an upper surface of said index plate.
32. A dirt removal apparatus for removing dirt from a drill bit
comprising; a. a plastically deformable body made of a material
which has a tacky surface to which dirt readily adheres, said
deformable body being movably supported by an actuator mechanism
effective in cyclically causing relative approaching motion between
said body and the tip of a drill bit to thereby cause said tip to
pierce said body, and relative retracting motion to retract said
body after said piercing container.
33. The dirt removal apparatus of claim 32 further including
reforming means for restoring said body to an original shape after
being deformed in contacting said drill bit tip.
34. The dirt removal apparatus of claim 33 wherein said reforming
means comprising at least one roller contacting a surface of said
body.
35. The dirt removal apparatus of claim 34 wherein said body has a
circular surface for pierceable contact with a drill bit tip.
36. The dirt removal apparatus of claim 35 wherein said body is
rollably mounted to said actuator mechanism.
37. The dirt removal apparatus of claim 36 wherein said actuator
means includes means for rolling said body while retracting said
body from said drill bit tip.
38. The dirt removal apparatus of claim 37 wherein said means for
rolling said body is further defined as comprising a one-way clutch
coupled between an axle fixed to said body and rollably held by
said actuator mechanism, and by an external member fixed to a
structure which pivotably supports a housing for said body, thereby
enabling said body to be pivoted towards and away from a drill bit
tip.
39. A method for processing drill bits comprising the steps of; a.
rotatably supporting on an index plate a plurality of
circumferentially spaced apart drill bit holders, b. locating a
plurality of processing unit stations spaced radially apart from
said drill bit holders, c. rotating said index plate to thereby
position a drill bit held in said holder at a particular one of
said processing stations located at a first index location, d.
automatically loading individual drill bits into individual ones of
said drill bit holders, e. automatically and simultaneously
performing separate processes on individual drill bits at said
processing stations, f. rotating said index plate to position said
drill bits at different index locations, and g. unloading
individual ones of said drill bits from said holders.
Description
BACKGROUND OF THE INVENTION
[0001] A. Field of the Invention
[0002] The present invention relates to methods and apparatus for
grinding the front cutting portion or tip of twist drill bits. More
particularly, the invention relates to an apparatus and method for
automatically grinding or re-pointing twist drill bits that
includes automatic means for removing dirt from the drill bit.
[0003] B. Description of Background Art
[0004] Printed wiring boards (PWB's) used to hold and electrically
interconnect electronic circuit components are typically fabricated
as laminated stacks of copper foil sheets alternating with
insulating sheets made of fiberglass, the latter containing glass
fibers imbedded within a solidified resin such as epoxy. Glass
fibers are highly abrasive, and can quickly dull drill bits used to
drill holes in a PWB for receiving component leads, or for forming
passageways or vias through the PWB. A typical PWB has a thickness
of about 0.062 inch, and has hundreds of holes drilled through it.
Each contact with the upper surface of a PWB to drill a hole is
referred to as a "hit." Since PWB's are usually arranged in stacks
of two to five boards for drilling, a corresponding number of holes
are drilled for each hit. Because the abrasive nature of the PWB
board materials dulls typical drill bits after about 3000-5000
holes are drilled, drill bits used for such applications must be
removed from service and re-sharpened after about 1,500-2,500
hits.
[0005] In conventional drill bit grinding apparatus used to sharpen
or re-point twist drill bits, the drill bit must be held in a chuck
while being re-pointed. Consequently, the operator must manually
perform operations such as inserting the drill into the chuck of a
drill bit holder mechanism, tightening the chuck to grip the drill,
positioning or aligning the drill in relation to the drill bit
holding mechanism and to rotary grinding stones, advancing the
drill bit towards grindstones, retracting the re-pointed drill bit
from the grindstones and removing the re-pointed drill bit. Because
of all of the aforementioned operations, an operator can usually
operate only a single drill bit grinding apparatus at a time. Thus,
even an experienced operator can typically re-point no more than
about 800 to 1,000 drill bits over an eight-hour work shift.
Therefore, there has been a strong demand for an automated drill
bit re-pointing apparatus that has a higher throughput rate than
existing re-pointing apparatuses, and which may be operated by less
than highly skilled personnel. Thus, for the small twist drill bits
which are used to drill holes in printed wiring boards (PWB's),
equipment has been developed for re-pointing the front cutting
portion of the bits including the tips, to thereby prolong the life
span of bits which would otherwise have to be disposed of for not
meeting dimensional tolerance requirements. Traditionally, the
re-pointing process requires as an initial step removal of dirt
which has inadvertently adhered to the drill bit. According to
customary prior art methods, dirt is removed from a bit prior to
re-pointing the bit by momentarily directing a blast of compressed
air onto the surface of the bit. Next, the bit is installed in a
clamping mechanism, and adjusted to a precisely pre-determined
spatial position and angular orientation or phase angle of the
flutes relative to abrasive grinding wheels. The grinding wheels
are then brought into contact with the front cutting portion of the
bit while the shank is rotated about the longitudinal axis of the
bit to thereby vary the angular orientation or phase angle of the
fluted portion of the bit presented to the grinding wheels. Upon
completion of the grinding operation, the bit must be cleaned a
second time, to remove particles of grindstone material, metal
chips, or oil which may have adhered to the bit. A quality control
inspection is then made of the bit to determine whether or not the
bit meets pre-determined quality control criteria. Also, a
ring-shaped collar is then customarily press-fitted onto the drill
bit shank to identify the size of the bit and to limit its
insertion depth into a workpiece.
[0006] Existing drill bit re-pointing apparatus functioning as
described above experience certain problems which limit their
effectiveness. For example, typical existing drill bit re-pointing
methods utilize physically separated work stations to perform the
various steps required in the re-pointing process. This arrangement
has the disadvantage of requiring time and personnel to transport
drill bits between the respective re-pointing stations, and of
requiring a relatively large installation space for the various
pieces of required equipment located at physically separated
stations.
[0007] Moreover, in utilizing prior art methods for removing dirt
from drill bits to prepare the bits for re-pointing, compressed air
commonly used for dirt removal is problematic for several reasons.
First, the small size of the bits and the preciseness of the
re-pointing operation necessitates that the compressed air have a
relative higher level of purity than normally required and supplied
for typical factory production operations. Second, use of
compressed air produces undesirable noise. Third, blasting dirt off
a bit with compressed air causes the dirt to be scattered in an
uncontrolled fashion to areas adjacent to the air gun.
[0008] In view of the problems mentioned above, the present
invention was conceived to accomplish the following objectives.
OBJECTS OF THE INVENTION
[0009] An object of the present invention is to provide an
automatic re-pointing apparatus and method for twist drill bits in
which batches of drill bits may be re-pointed by a sequence of
steps performed at a single location by an automatic re-pointing
apparatus.
[0010] Another object of the invention is to provide apparatus and
method for removing dirt from a drill bit to be re-pointed, by an
automatic removal apparatus which does not require use of
compressed air.
[0011] Various other objects and advantages of the present
invention, and its most novel features, will become apparent to
those skilled in the art by perusing the accompanying
specification, drawings and claims.
[0012] It is to be understood that although the invention disclosed
herein is fully capable of achieving the objects and providing the
advantages described, the characteristics of the invention
described herein are merely illustrative of the preferred
embodiments. Accordingly, I do not intend that the scope of my
exclusive rights and privileges in the invention be limited to
details of the embodiments described. I do intend that equivalents,
adaptations and modifications of the invention reasonably inferable
from the description contained herein be included within the scope
of the invention as defined by the appended claims.
SUMMARY OF THE INVENTION
[0013] Briefly stated, the present invention comprehends an
apparatus for pointing twist drill bits, the apparatus including at
least one and preferably two dirt removal mechanisms.
[0014] A drill bit pointing and dust removal apparatus according to
the present invention includes a drill bit processing unit which
has a rotary index plate on which are mounted a plurality of
circumferentially spaced apart drill bit holder units. Spaced
radially apart from the periphery of the index plate are a
plurality of circumferentially spaced apart, fixed drill bit
processing stations where separate processing units each perform a
separate processing function on an individual drill bit which has
been rotated by the index plate into position adjacent to a
particular station. Spaced radially apart from the periphery of the
rotary pedestal are a plurality of circumferentially spaced apart
operation stations where separate operation units each perform a
separate operation on an individual drill bit which has been
rotated by the rotary pedestal into position adjacent to a
particular operation station. The loading unit includes a loading
unit which has a rotary pedestal on which are located a plurality
of circumferentially spaced apart transfer arms, each adapted to
hold a separate drill bit. The apparatus includes actuator
mechanisms which transfer an individual bit from an arm on the
loading unit rotary pedestal to an individual drill bit holder on
the processing unit index plate at the beginning of a drill bit
processing cycle, and from an individual drill bit holder to an arm
on the loading unit base plate at the end of a process cycle. The
loading unit rotary pedestal is then rotated to transfer a
processed drill bit to a reject container station, ring adjustment
station, and input/output station located in a circle around the
periphery of the loading unit pedestal, to be scrapped if
defective, or fitted with an identification ring and unloaded from
the loading unit base plate into a transport container for
transport away from the apparatus, e.g., to a shipping
location.
[0015] The apparatus according to the present invention includes
position control mechanisms which consist of operatively
interactive sensors and actuators located at fixed processing
stations and on each multi-purpose drill bit holder unit on the
processing unit index plate. The position control mechanisms
include a tip position adjustment mechanism which maintains the tip
of a drill bit in a predetermined, fixed position, a center
adjustment mechanism that positions the center of the drill bit
core at a predetermined elevation, and a phase-adjustment mechanism
which adjust the rotation angle or phase of the bit to
predetermined values.
[0016] According to the invention, a drill bit to be subjected to
re-pointing and/or other processes by the apparatus is first loaded
onto an arm on the rotary pedestal of the loading unit at an
input/output station. The rotary pedestal is then rotated to a
pre-grind dirt removal operation station, where dirt is removed
from the drill bit. Next, the rotary pedestal is rotated to a
load/unload station adjacent to the processing unit, where the
pre-cleaned bit is transferred to the index plate of the processing
unit. According to the invention, an individual drill bit in a
holder on the processing unit index plate successively encounters a
series of drill bit processing stations located adjacent to the
periphery of the processing unit index plate, including in order,
an optical tip position set up sensing and alignment station for
providing control signals which are used to adjust the position of
the drill bit, a grinding station, a second, post-grind dirt
removal station, and an optical inspection station.
[0017] A dirt removal apparatus for removing dirt from a drill bit
tip according to the present invention includes a plastically
deformable body which has a tacky surface, and an actuator
mechanism for bringing the body into contact with a drill bit tip,
whereupon dirt lightly adhered to the drill bit adheres more
strongly to the tacky surface of the body, thus removing the dirt
from the bit when the body is retracted from the bit. In a
preferred embodiment, the dirt removal body has the form of a
rotatable toroidal roller made of a synthetic polymer such as
poly-isobutylene, that is easily deformable and has a tacky
surface. The actuator mechanism pivots the toroidal roller into
contact with a drill bit tip to clean the tip, and pivots the
roller away from the tip, with dirt originally adhered to the drill
bit surface now adhered to the roller. Pivotal motion of the dirt
removal toroidal roller away from the tip causes the roller to
rotate relative to silicone rubber dressing rollers which contact
surfaces of the toroidal roller to thereby re-shape and re-surface
the toroidal body, after it has been deformed and soiled in the
process of cleaning a drill bit, thus preparing the toroidal roller
to contact and clean a next drill bit.
[0018] Repointing of drill bits according to the method of the
present invention includes the following steps. First, a drill bit
is loaded onto one of the plurality of drill bit transfer arms
mounted on the rotary pedestal of the loading unit which is
adjacent to an input/output, or carry in/carry out station spaced
radially outwards from the periphery of the loading unit base
plate. The loading unit rotary pedestal is then rotated a
predetermined angle to position the bit adjacent to a first,
pre-grind dirt removal processing station, where the bit is
cleaned: the loading unit rotary pedestal is then rotated a
predetermined angle to a loading/unloading transfer station located
between the loading unit and processing unit, where the cleaned bit
is then loaded onto an empty drill bit holder on the processing
unit index plate by actuation of the transfer arm holding the bit.
The processing unit index plate is then rotated a first angular
increment to locate the bit holder and bit adjacent to a tip
position set up processing station where an electro-optical sensing
apparatus views the bit and in response to that view, produces
control signals which are applied to actuator mechanisms which
adjust the position of the tip of the drill bit to a predetermined
location in the field of view of the sensing apparatus, adjust the
height of the center of the bit, and adjust the rotation angle or
phase angle of the fluted portion of the tip to a predetermined
angle relative to a reference plane. The index plate is once again
incrementally rotated to position the drill bit holder and drill
bit adjacent to a grinding wheel station which has a pair of
rotating grindstones mounted on a traverse mechanism which
translates the rotating grindstones forcibly against surfaces of a
drill bit to thereby automatically grind the tip to a predetermined
shape. The index plate is again rotatably incremented to position
the drill bit holder and bit adjacent to a second, post-grind dirt
removal station, where the bit is again cleaned. Next, the index
plate is incrementally rotated to position the ground and cleaned
re-pointed drill bit adjacent to an electro-optical inspection
station, which uses a computer and pattern recognition logic to
determine whether the re-pointed drill bit meets size and shape
specifications. The index plate is once again rotated to position
the drill bit holder holding the re-pointed, cleaned, and inspected
drill bit back at the loading/unloading transfer station, adjacent
to an empty transfer arm on the pedestal of the loading unit,
whereupon the transfer arm is actuated to grasp and remove the
processed bit. The loading unit rotary pedestal is then
incrementally rotated to position the transfer arm holding the
re-pointed bit adjacent to a reject container, at which location
the arm is actuated to deposit a rejected bit into the reject
container. The loading unit rotary pedestal is then incrementally
rotated to position the transfer arm holding an acceptable
re-pointed drill bit adjacent to a ring installation unit, where an
identifying ring press-fitted onto the shank of the bit is adjusted
to a proper distance from the drill bit tip. The loading unit
rotary pedestal is then incrementally rotated to position the drill
bit transfer arm holding a finished re-pointed bit adjacent to the
input/output station, where the transfer arm transfers the bit to a
transport container.
[0019] The processing unit index plate and loading unit pedestal
have equal numbers, e.g., five, of drill bit holders and transfer
arms, respectively, which are separated by the same central angles,
e.g., 72 degrees. Also, the relative positions and movements of the
drill bit holders and transfer arms, as well as functions of the
processing and loading stations, are synchronized by a transport
control unit, which comprises a microprocessor or general purpose
computer such as a PC, which also synchronizes rotations of the
processing unit index plate and the loading unit pedestal.
Therefore, each of the foregoing operations described at the
various stations adjacent to the processing unit and loading unit
are performed simultaneously on five different drill bits, thus
resulting in a high processing through-put rate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a partly diagrammatic upper plan view of a drill
bit pointing and dust removal apparatus according to the present
invention.
[0021] FIG. 2 is a partly sectional elevation view of a transport
mechanism and drill bit holder of the apparatus of FIG. 1.
[0022] FIG. 3 is a vertical longitudinal sectional view of the
drill bit holder of FIG. 2.
[0023] FIG. 4 is an upper plan view of a drill bit phase adjustment
mechanism comprising part of the apparatus of FIG. 1.
[0024] FIG. 5 is a vertical longitudinal sectional view of the
loading unit component of the apparatus shown in FIG. 1.
[0025] FIG. 6 is a partly vertical sectional, party diagrammatic
view of an optical apparatus, similar versions of which comprise a
component of both a tip position set up processing unit and
inspection processing unit of the apparatus of FIG. 1.
[0026] FIG. 7 is an upper plan view of the apparatus of FIG. 6.
[0027] FIG. 8 is a fragmentary upper plan view of a grinding
process unit comprising a component of the apparatus of FIG. 1.
[0028] FIG. 9 is a partly sectional front elevation view of a dirt
removal processing unit comprising part of the apparatus of FIG.
1.
[0029] FIG. 10 is a side elevation view of the structure of FIG. 9,
taken in the direction of line A-A.
[0030] FIG. 11 is a fragmentary end elevation showing the upper
part of the dirt removal processing unit of FIG. 9.
[0031] FIG. 12 is a side elevation view of the structure of FIG.
11, taken along line B-B.
[0032] FIG. 13 is an oblique view of the structure of FIG. 12,
taken in the direction of line C-C.
[0033] FIG. 14 is an upper plan view of a ring adjustment unit
comprising part of the apparatus of FIG. 1.
[0034] FIG. 15 is a side elevation view of the structure of FIG.
14, taken in the direction of line D-D.
[0035] FIG. 16 is an end elevation views of the structure of FIG.
15, taken in the direction of line E-E.
[0036] FIG. 17 is a flow chart showing the workflow of the
apparatus of FIG. 1.
[0037] FIG. 18 is a flow chart showing steps in the adjustment of
axial tip position, core elevation, and phase adjustment of drill
bit processed by the apparatus of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] FIGS. 1-18 illustrate the structure and function of a drill
bit pointing and dust removal apparatus and method according to the
present invention. From the ensuing description, it will be clear
that certain novel components of the apparatus and method may be
used apart and/or independently from the apparatus and method as a
whole. For example, the novel dirt removal unit described below may
be used independently of other components of the apparatus.
[0039] Referring first to FIG. 1, an automatic drill bit
pointing/re-pointing and dust removal apparatus 20 according to the
present invention may be seen to include a drill bit processing
unit 21 which includes a base plate 27 and a longitudinally
disposed circular disk-shaped index plate 22 supported above the
base plate and rotatable with respect to the base plate.
Re-pointing apparatus 20 also includes a loading unit 36 that has a
base plate 37 which rotatably supports a plurality of
circumferentially spaced apart drill bit manipulating arm
mechanisms 154 mounted on a rotary pedestal 148 supported above the
base plate and rotatable in a plane parallel and adjacent to index
plate of processing unit 21. Mounted onto the upper surface of
index plate 22 of processing unit 21 are a plurality of
circumferentially spaced apart drill bit holder units 28 each
adapted to hold an individual drill bit 26, as shown in FIG. 2. In
a preferred embodiment, index plate 22 mounts five drill bit holder
units 28 spaced apart from one another at 72-degree intervals.
Also, rotary pedestal 148 of loading unit 36 preferably mounts five
arm mechanisms 154 spaced apart from one another at 72-degree
intervals.
[0040] Surrounding index plate 22 of processing unit 21 is a fixed
arrangement of circumferentially spaced apart drill bit processing
units or stations of various types, the structure and function of
which are described in detail below. The processing units include a
pre-grind dirt removal unit 46, tip position setup unit 38,
grinding unit 40, post-grind dirt removal unit 42, and inspection
unit 44. The five above-described drill bit processing units are
spaced apart at the same angular increments as drill bit holder
units 28. Thus, when index plate 22 is rotated to position a
particular drill bit holder 28 adjacent to a particular processing
unit, e.g., pre-grind dirt removal unit 46, for the purpose of
performing a process step on a particular drill bit held by that
holder, the other four drill bits held by the other four drill bit
holders 28 will be positioned adjacent to respective ones of the
four other processing units. This arrangement enables apparatus 20
to sequentially perform five different processes on five individual
drill bits simultaneously.
[0041] As shown in FIG. 1, each drill bit holder unit 28 is
installed obliquely to the radial direction of index plate 22.
Thus, the maximum radial projection of drill bit holder unit 28
beyond the periphery of index plate 22 is minimized, thereby
minimizing the floor space area or footprint required for
processing unit 21. The oblique orientation of drill bit holder
units 28 relative to index plate 22 also locates the tips of drill
bits held in the holder units close to the center of index plate,
thus enabling drill bit tips to be more precisely positioned
relative to peripheral processing units for a given error tolerance
in the angular rotation angles of the index plate. In addition to
the advantage of arranging drill bit holders 28 obliquely relative
to radii of index plate 22, as shown in FIG. 1, each holder 28 is
so constructed as to hold a drill bit 26 at an oblique angle, e.g.,
45 degrees to the plane of index plate 22, as shown in FIG. 2. This
arrangement reduces bending of a drill bit 26 during processing,
and further improves the precision with which the drill bit may be
located relative to a processing station.
[0042] An understanding of the structure and function of index
plate 22 may be facilitated by reference to FIG. 2, which shows an
individual one of a plurality of drill bit holder units 28 mounted
to the index plate. As shown in FIG. 2, in the center of index
plate 22 is installed a cylindrical revolving shaft 60 which is
electrically coupled to a revolving electrode 62 via a cylindrical
coupling 63. Inside the bore of revolving shaft 60 is disposed an
electrical cable (not shown) which is connected at one end to a
motor 84 which is used for a phase adjustment that is described
later, conductors of the cable being connected at the other end of
the cable to revolving electrode 62. Because the cable revolves in
unison with revolving shaft 60, twisting of the cable is
prevented.
[0043] Horizontally aligned with a lower part of revolving shaft 60
is an index drive motor 64 which is fastened to a support 61. Index
drive motor 64 has a shaft 66 which protrudes vertically upwards
from the motor housing. A driving gear 68 fixed to the upper end of
motor shaft 66 meshes with and rotatably drives a driven gear 70
attached concentrically to the lower surface of index plate 22.
Thus, when motor 64 is supplied with electrical power, motor shaft
66, driver gear 66, driven gear 70 and index plate 22 are rotated.
Motor 64 is controlled so that each of the drill bit holder units
28 on index plate can be sequentially brought into position and
stopped facing each of the above-mentioned processing units. A
ring-shaped thrust bearing 65 mounted concentrically below index
plate 22 rotatably supports the index plate, the thrust bearing
having a notch which provides clearance for driving gear 68.
[0044] Drill bit holder unit 28, shown in elevation view in FIG. 2,
is shown in a more detailed, partly sectional view in FIG. 3. The
function of drill bit holder unit 28 is to hold the tip of a drill
bit 26 in a vertical plane, at an oblique angle, e.g., 45 degrees,
with respect to the upper horizontal surface of index plate 22.
Holder unit 28 has a base 80 installed above index plate 22. As
shown in FIG. 3, holder unit 28 includes a vertically disposed
mount or support structure 82 which protrudes upwardly from base
80, near the outer circumferential side or peripheral edge of index
plate 22. Fixed to the outer side of support structure 82 is an
edge receptacle section 128 for supporting the front fluted cutting
portion of a drill bit 26.
[0045] As shown in FIGS. 2 and 3, drill bit holder 28 has a phase
angle adjuster mechanism 130 which includes a motor 84 for
adjusting the phase of drill bit 26. Phase is here defined as the
rotation angle or polar angle about the longitudinal axis of the
bit of structural features such as the chisel point or flutes of
the drill bit tip, relative to a fixed reference plane containing
the longitudinal axis. As shown in FIGS. 2 and 3, phase adjuster
motor 84 is located near the center of base plate 80, the motor
having an output shaft angled upwardly and radially outward at an
oblique angle, e.g., 45 degrees from base plate 80. A block-shaped
phase mechanism support body 86 located between motor 84 and drill
bit 26 supports the butt end of the drill bit shank, and contains a
mechanism driven by the motor shaft for rotating the bit around the
longitudinal axis of the shank to thereby adjust the phase angle of
the bit, as will be described below. The structure and function of
a drill bit support mechanism 120 which functions with phase angle
adjustment mechanism 130 may be best understood by referring to
FIG. 4 in addition to FIGS. 2 and 3. As shown in FIG. 4, the shank
of a drill bit 26 is rotatably supported on adjacent
circumferential surfaces of a pair of laterally spaced apart rubber
rollers 122, which are located at the outer, front, or "tip" side
of phase mechanism support body 86. The drill bit shank is held
rotatably in contact with rollers 122 by a ring-shaped idler
bearing 124 rotatably mounted at the end of an L-shaped pivot arm
126, the lower surface of the idler bearing pressing down against
the upper surface of the shank when pivot arm 126 is pivoted
downwards towards the shank, as shown in FIG. 3. A spring (not
shown) biases pivot arm 126 in a downward direction, thus causing
idler bearing 124 to be resiliently pressed against the upper
surface of a drill bit shank.
[0046] As shown in FIG. 3, pivot arm 126 has an L-shaped cross
section, and includes a short rear tail side leg 126A which
protrudes outwardly relative to phase mechanism support body 86. A
driver cam (not shown) having a surface pressuring against leg 126A
of pivot arm 126 is rotated to rotate pivot arm 126 on fulcrum arm
127 (see FIG. 2) in the direction of the arrow mark 129 in FIG. 3.
With pivot arm 126 and idler bearing 124 pivoted clockwise from the
position shown in FIG. 3, a drill bit 26 may be removed from or
inserted in place on rollers 122 of drill holder mechanism 126.
[0047] The operation of phase adjustment mechanism 130 of drill bit
holder unit 28 may be best understood by referring to FIG. 4. As
shown in FIG. 4, drill bit phase adjustment mechanism 130 includes
a pair of laterally spaced apart gear wheels 132 which are each
fixed to the rear end of a separate one of a pair of parallel,
longitudinally disposed drive shafts (not shown) rotatably held
within support block 86. Gear wheels 132 mesh with a pinion gear
134 fixed to the shaft of phase control motor 84. The
above-mentioned drive shafts protrude forward from support body 86,
where they are fixed to adjacent rollers 122. Thus, when the shaft
of motor 84 is rotated in response to control signals, gear wheels
132 and rollers 122 are rotated in unison, thus rotating the shank
of drill bit 26, which is pressed against rollers 122 by idler
bearing 124, to a particular phase angle.
[0048] As shown in FIG. 3, drill bit holder unit 28 includes a
horizontal slider system 88 for precisely adjusting the axial tip
position of a drill bit 26 held by the holder unit, and a vertical
slider system 90 for adjusting the inclination angle of the drill
bit. Horizontal slider system 88 includes a horizontally disposed
plate 94 which is radially slidably located within a horizontally
disposed groove 92 within base 80. Plate 94 has located at an inner
radial end thereof a downwardly protruding lever 96. Plate 94 also
has formed near an inner radial end thereof, in the upper surface
thereof, a wedge-shaped depression 95 which has a lower surface
which slopes downwardly and radially outwardly. In a web portion of
base plate 80 above depression 95 is a vertically disposed
cylindrically through-bore 98 which penetrates the lower surface of
the web and the upper surface of the base plate. A
cylindrically-shaped headed pin 100 is vertically reciprocally
located in bore 98. Pin 100 has a lower convex surface which
slidably rides on the sloping bottom surface of depression 95.
[0049] Horizontal slider system 88 includes a motor 110. Motor 110
is located below lever 96, and fixedly mounted to a support
structure (not shown) comprising part of tip position set-up
processing unit 38, spaced radially apart from base plate 80.
Horizontal slider system 88 includes a rack and pinion mechanism
112, which includes a pinion gear 112a fixed to the shaft of motor
110, and a radially disposed rack 112b which meshes with the pinion
gear, and which is reciprocally translatable in response to
rotation of the motor shaft in opposite directions. A pin 114
protrudes vertically upwards from rack 112b near the rear or inner
radial end of the rack. Pin 114 is radially aligned with lever 96
on slider plate 94, and protrudes above the lower edge of the
lever. Thus, when motor 110 is energized in a direction which
causes rack 112b to move radially outwards, i.e., to the left in
FIG. 3, pin 114 abuts lever 96 and pulls horizontal slider plate 94
radially outwardly, thus adjusting the axial tip position of a
drill bit 26, in a manner described below. After the tip of drill
bit 26 has been thus positioned, motor 110 is powered in a reverse
direction, causing rack 112b to move to the right in FIG. 3,
disengaging linkage between pin 114 and lever 96.
[0050] After completion of grinding, dirt removal, and final
inspection steps of a drill bit at respective processing units
following in sequence after the tip position set up processing
unit, an air cylinder (not shown) located at a position between
processing unit 21 and loading unit 36 (see FIG. 1) where a
processed drill bit is unloaded from processing unit 21 to loading
unit 36, pushes radially inwards on lever 96 to restore slider
plate 94 to its radially innermost position, or extreme right-hand
position in FIG. 3.
[0051] Referring now to FIGS. 2 and 3, it may be seen that drill
bit holder unit 28 of apparatus includes a vertical slider
mechanisms 90 for adjusting the height of the tip of a drill bit
26. Vertical slider mechanism 90 is substantially similar in
structure and function to horizontal slider system 88 described
above. Thus, as shown in FIG. 3, vertical slider mechanism 90
includes a motor 110b which is mounted fixedly to a structure
member (not shown) of tip position setup processor unit 38.
Vertical slider mechanism 90 also includes a vertically disposed
slider plate 94b having at its lower end a horizontally disposed,
radially outwardly protruding lever 96b. As shown in FIG. 2,
vertical slider mechanism 90 includes a rack and pinion mechanism
113 comprised of pinion gear 113a fixed to the shaft of motor 110b,
and a vertically disposed rack 113b which meshes with the pinion
gear. A horizontally disposed pin 115 protrudes radially outwards
from rack 113b, near the upper end of the rack, the pin being
vertically aligned with lever 96b protruding radially outwards from
vertical slider plate 94b. Thus, when motor 110b is energized, pin
115 is moved in a vertical direction, and comes into contact with
lever 96b of vertical slider plate 94b, causing the vertical slider
plate to move in a vertical direction. This action causes the
height of the tip of drill bit 26 to be adjusted, as well as the
elevation angle of the shank, in a manner which will now be
described in detail.
[0052] As shown in FIG. 3, vertical slider mechanism 90 includes a
follower plunger 100b comprising a headed pin which has a shank
which protrudes radially inwardly against the sloping inner surface
of a generally vertically disposed depression 95b formed in the
radially outward vertical surface of vertical slider bar 94.
Plunger 100b is resiliently pressed against the sloping inner
surface of depression 95b by a spring (not shown). Thus, an edge
support receptacle or yoke 128 which is located at the upper end of
an arm 128a and supports the tip of a drill bit 26, is pivoted in
vertical plane when the lower end of the arm, which is attached to
follower plunger 100b, is moved outwards and inwards as plate 94b
is moved downwards and upwards, respectively, thus causing yoke 128
to rotate clockwise and counterclockwise, respectively, and thereby
raising or lowering the tip of drill bit 26.
[0053] As shown in FIG. 3, the inner end of follower plunger 100b
is resiliently biased by a spring (not shown) against the sloping
inner surface of depression 95b in vertical slider plate 94b. Thus,
since that sloping surface is angled upwardly and outwardly with
respect to vertical plane parallel to vertical slider plate 94b,
downward motion of the vertical slider plate pushes follower
plunger radially outwards; thus the upper end of arm 128 attached
at its lower end to follower plunger 100b is pivoted in a clockwise
direction in FIG. 3, changing the inclination angle of a drill bit
26 whose tip is supported by yoke 128 at the upper end of the arm.
Lever 96b is moved upwards to its uppermost position and lever 96
to its rightmost position at the end of a drill bit processing
sequence, by a cam (not shown).
[0054] Horizontal slider mechanism 88 adjusts the axial or
longitudinal position of the tip of a drill bit 26 relative to base
80, as follows. As shown in FIG. 3, a generally
cylindrically-shaped, elongated bore 102 is provided through
support body 86, in axial alignment with the longitudinal center
line of drill bit 26 held in drill bit holder unit 28. Bore 102
contains an elongated helical compressive spring 106, the upper end
of which is retained in the bore by an upper ring-shaped spring
retainer 107a. The lower end of spring 106 bears resiliently
against the annular shoulder of a cylindrical head 107b formed at
the end of elongated cylindrical push rod 104. Spring 106 causes
the upper circular face end of push rod 104 to bear resiliently
against the circular shank end face of a drill bit 26, and the
lower end face of rod head 107b, which protrudes from the rear
opening of bore 102, to bear resiliently against the first, upper
obliquely angled arm or link 108a of a V-shaped link mechanism or
bell crank 108. Bell crank 108 also has a second, lower
horizontally rearwardly disposed arm or link 108b. Bell crank 108
is preferably connected to support 80 by a pivot pin 111 disposed
horizontally through link arms 108a and 108b at their V-shaped
junction.
[0055] Referring still to FIG. 3, it may be seen that follower
plunger 100 is fastened at its upper, head end to the rear end
portion of horizontally disposed linkage arm 108b. As a result,
compressive force exerted on the inner face of push rod head 107b
by compression spring 106 causes a downward and rearward force to
be exerted on the link arm 108a of bell crank 108. Thus, bell crank
108 is biased resiliently clockwise around pivot pin 111, as seen
in FIG. 3, thus causing horizontal bell crank arm 108b to force
follower plunger into resiliently compressive contact with the
sloping lower surface of depression 95 in horizontal slider plate
94. This compressive force in combination with friction forces
exerted on horizontal slider plate 94 by the adjacent walls of slot
92 in support base 80, maintains the slider plate in a fixed
position relative to the support base 80. As shown in FIG. 3,
radially outward motion of slider plate 94 causes the tip of a
drill bit 26 held in holder 28 to move axially forward, while
inward motion of the slider plate causes the tip to move axially
inward with respect to yoke 128.
[0056] FIG. 5 is a vertical central longitudinal sectional view of
loading unit 36 of apparatus 20. Loading unit 36 receives
individual drill bits 26 from input/output sation 22 and delivers
individual bits to drill bit holder units 28 on index plate 22 of
processing unit 21. Loading unit 36 has a horizontally disposed
base platform 37 which has protruding perpendicularly upwards
therefrom a central vertically disposed shaft 140. The lower end of
shaft 140 is linked to a pneumatic actuator cylinder (not shown)
for moving shaft 140 reciprocally in a vertical direction, as shown
by the double headed arrow in FIG. 5. Shaft 140 is located
concentrically within the bore of a longitudinally elongated
cylindrical sleeve 142. Sleeve 142 has an upper longitudinal
portion of larger outer diameter than the lower portion thereof; a
rotary pedestal 148 concentrically receives the upper end of the
sleeve. Protruding vertically upwards from the upper surface of
rotary pedestal 148 are five arm support mounts 150 spaced
circumferentially apart at 72-degree intervals. The lower end of
sleeve 142 fits within a cylindrical collar 144 located above base
plate 37. Collar 144 has disposed radially through a cylindrical
side wall thereof a radially disposed vacuum passageway 145 which
is connected at an outer radial entrance opening thereof to a
vacuum source (not shown), and at an inner radial end thereof to a
location radially aligned with a cylindrically-shaped vacuum
passageway within sleeve 142. As shown in FIG. 5, passageway 160
inside cylinder 142 has in sectional view an L-shape, the bottom
horizontal leg of the L being a sectional view of a ring-shaped
opening. The upper end of vacuum passageway 160 is connected to a
radially disposed coupling hole 141. A hollow plug-shaped stopcock
143 on the upper end of vacuum passage 160 forms an air-tight seal
therewith. Collar 144 is fixed to base plate 37 through a bracket
147. A ring-shaped roller bearing located concentrically within
collar 144 allows free rotation of cylinder 142, which passes
through the central bearing opening, with respect to base plate
37.
[0057] Loading unit 36 includes generally a cylindrically-shaped
arm mechanism actuator spool 152 which fits concentrically over the
upper end of central shaft 140, and is secured thereto by a nut
149. Actuator spool 152 has a circular plan view shape, and has
formed in the cylindrical wall surface thereof an annular
ring-shaped groove 152a which has in transverse cross section an
H-shape. A ball 153 attached to an inner radial end of an inner
lever arm 154a of each of the five arm mechanisms 154 is pressed
resiliently upwardly against the upper surface of groove 152a by
means of a vertically disposed tension spring 157 connected at an
upper end thereof to an outer arm portion 154b of arm mechanism
154, and at a lower end thereof to arm mechanism mount bracket 150.
The outer end of inner lever arm 154 is joined obliquely by a set
screw (not shown) to the inner end of outer arm portion 154b at a
junction plate which is pivotably mounted by a horizontally
disposed pivot pin 159 to the upper end of mount bracket 150. Outer
arm 154b has attached to its outer end an air chuck arm 155 which
releasably holds a drill bit 26 at the outer end of the air chuck
arm. When spool 152 is translated down and up by shaft 140, air
chuck arm 155 is pivoted from a radially outwardly and downwardly
angled orientation, as shown in the right side of FIG. 5, to a
horizontally disposed orientation, as shown on the left side of
FIG. 5.
[0058] As shown in FIG. 5, air chuck 155 has through an outer
surface thereof a vacuum passage 156 that makes contact with a
drill bit 26 held in the air chuck. A flexible vacuum hose 158 is
connected at one end thereof to an inner end of vacuum passage 156.
The other end of vacuum hose 158 is connected to coupling hole 141
in cylinder 142. Thus, when vacuum intake hole 145 in collar 144 is
coupled to a vacuum source, a pressure reduction is communicated
through vacuum passage 160 in cylinder 142, through coupling hole
141, through hose 158 and through vacuum passage 156 in air chuck
155 to the surface of the shank of a drill bit 26 positioned
adjacent to the chuck; thus atmospheric pressure forces the shank
into contact with opening of vacuum passage 156, and thereby causes
the bit to be firmly held in the air chuck.
[0059] Referring still to FIG. 5, it may be seen that a driving
gear 146 fits concentrically over the lower end of cylinder 142,
and is secured to the cylinder. Gear 146 meshes with and is driven
by a driving gear attached to a motor (not shown). Thus, when the
motor is energized, cylinder 142 and rotary pedestal 148 attached
to the upper end of the cylinder are rotated. As rotary pedestal
148 rotates, each of the five arm mechanisms 154 attached to a
separate mount 150 protruding upward from the rotary pedestal
rotates integrally with the rotary pedestal; and each ball 153 at
the inner end of each arm 154a rolls in contact with the upper
surface of groove 152a in spool 152. During this rotary motion,
central shaft 140 can be made to move vertically in synchronization
with rotary motion of arm 154 relative to spool 153, in response to
actuation of the above-mentioned pneumatic cylinder (not shown).
Vertical motion of spool 153 in turn causes each air chuck 155 to
pivot as indicated by the curved double-headed arrow 161 in FIG. 5.
Depending upon the angle formed between air chuck 155 and outer arm
154b, the length of arm 154a, location of pivot pin 159, and
distance of vertical excursion of spool 152 between up and down
positions shown in FIG. 5, drill bit 26 can be held in various
orientations ranging between vertical and horizontal. In the
embodiment of the present apparatus depicted in FIG. 5, the
inclination of the shank of drill bit 26 ranges between about 45
degrees, as shown on the right of FIG. 5, to a horizontal
orientation, shown on the left of FIG. 5.
[0060] The structure and function of tip position set up process
unit 38 will now be explained. It will be recalled that inspection
process unit 44 has a substantially similar construction, and
performs optical imaging functions substantially similar to those
of set up process unit.
[0061] Referring now to FIGS. 6 and 7, tip position set up process
unit 38 may be seen to include a longitudinally elongated,
rectangularly-shaped, box-like mount 171 which has a hollow
interior space, and is fixed to a base (not shown) with the
longitudinal axis of the mount inclined at an angle of 45 degrees
to a radius of index plate 22, as shown schematically in FIG. 1. At
the front end (left end in FIG. 6) of mount 171 a bracket 171a is
provided that extends to the bottom of a field lens 186. A first,
upper light source compartment 182 for detecting the position of
the tip of a drill bit 26 is attached to a front end part of
bracket 171a. Light source compartment 182 produces a beam of light
which is directed downwardly towards the tip of drill bit 26
towards a prism 187 located within the front end portion of mount
171, the light entering mount 171 through a window.
[0062] As shown in FIG. 6, tip position set up process unit 38
includes an optical position control photo sensor 188 located
within mount 171 near the rear or right-hand end of the mount.
Position control photo sensor 188 faces the exit pupil of prism
187, and has a field of view which includes the exit pupil. Thus,
light emitted from light source 182 and illuminating the tip of
drill bit 26 enters the entrance pupil of prism 187, is bent 90
degrees, and is detected by position control photo sensor 188.
Therefore, when a drill bit held in a drill bit holder unit 28 on
index plate 22 is positioned in the space between light source 182
and prism 187, light emitted from source 182 and scattered by the
drill bit tip into prism 187 is received by position control photo
sensor 188, which generates electrical signals which are used to
control the tip position.
[0063] As shown in FIGS. 6 and 7, tip position set up process unit
38 includes a longitudinally elongated mirror tube 173 fixed to the
upper side of mount 171, in parallel alignment therewith.
Protruding longitudinally forward from the front transverse end
wall of tubular mirror tube 173 is a telescope tube 172
longitudinally aligned with the longitudinal axis of a drill bit
26.
[0064] As shown in FIG. 7, a pair of light sources 184 located on
opposite horizontal sides of the longitudinal optical axis of
telescope tube 172, angled obliquely to the optical axis thereof,
project beams of light obliquely forward to obliquely illuminate
the tip of a drill bit 26. As shown in FIGS. 6 and 7, a CCD camera
178 located above telescope tube 172 and having an optical axis
parallel to that of the telescope tube has a rearwardly directed
entrance pupil located forward of mirror tube 173. A trapezoid-like
prism 179 is located within mirror tube 173, near the front end
thereof, the prism being so arranged as to conduct light traveling
rearward from the tip of a drill bit 26 illuminated by light
sources 184, and passing through field lens 186, onto the focal
plane of CCD camera 178, thus allowing the drill bit point to be
photographed by the CCD camera. CCD camera 178 is linked to a
personal computer (PC) (not shown) and the photographed image of
the surface of drill bit tip 26 is displayed on the display monitor
of the PC. The PC contains pattern recognition and control software
which are responsive to an image of the drill bit tip in generating
control signals which are used to adjust the position of the tip
and center of a drill bit 26, by controlling horizontal slider
motor 110 and vertical slider motor 110b, as well as controlling
phase adjustment motor 84 to thereby adjust the angular orientation
or phase of the drill bit. Mirror tube 173 contains a
longitudinally disposed rotatable shaft which at the front end
thereof threadingly engages a nut attached to a member which holds
prism 179; the rear end of the shaft protrudes outwardly from the
rear end wall of mirror tube 173, and has attached thereto a hand
wheel and dial which may be turned to thereby move prism 179
longitudinally forward and rearward inside the mirror tube, thus
reducing or enlarging the size of the drill bit point image
received by the CCD camera.
[0065] FIG. 8 illustrates the structure and function of the point
grinding processing unit 40 of apparatus 20. As shown in FIG. 7,
point processing unit 40 includes a second surface grindstone 190
which is used to grind a second surface of the tip of a drill bit
26, and a third surface grindstone 192 which is used to grind the
third surface of the tip. Grindstones 190 and 192 are rotated by a
pair of separate drive motors 194, and are inclined at an
appropriate bevel angle with respect to the longitudinal axis of
the bit, so as to grind second and third surfaces of the drill bit
tip to form an appropriate geometrical shape. Moreover, grindstones
190 and 192 are attached to a table 196 which is inclined to the
axis of the drill bit, the table being automatically driven by a
traverse mechanism, parallel to the longitudinal axis of the table,
and obliquely to the drill bit, as shown by the double-headed arrow
198.
[0066] Referring now to FIG. 1 in addition to FIG. 8, it may be
seen that point processing unit 40 is made to rotate in the
direction indicated by the double-headed, curved arrow 40b, about
axis 40a. As shown in FIG. 1, a grindstone face resurfacing machine
40c is located next to point processing grindstone unit 40. Machine
40c is used to periodically repair or resurface faces of
grindstones 190, 192, which become worn after grinding and
polishing a sufficient number of drill bits 26. Face dressing
machine 40c includes separate grindstones for resurfacing second
surface grindstone 190 and third surface grindstone 192. The face
dressing grindstones are driven by stepper motors and are so
constructed and arranged as to be able to cut deeply and
automatically into the surfaces of second surface grindstone 190
and third surface grindstone 192, to resurface the two grindstones
to predetermined contours. To perform the re-surfacing of
grindstones 190 and 192 by resurfacing machine 40c, drill bit
pointing unit 40 is periodically made to rotate in the direct 40b,
thus presenting the second and third surface grindstone to face
re-surfacing grindstones in machine 40c.
[0067] FIGS. 9-13 illustrate the structure and function of a dirt
removal processing unit 42. Dirt removal processing unit 42 is used
to remove dirt, scrap, grindstone particles, metal chips and other
foreign matter from a drill bit 26, both prior to and after the bit
has been ground during a re-pointing process. Dirt removal
processing unit includes a support 210, to which is attached a
synchronous motor 212. A ring 213 fixed to the shaft of motor 212
has attached eccentrically to an outer surface thereof the lower
end of a link mechanism 214. The upper end of link 214 is coupled
to a lever 214a, which is mounted to an upper end portion of
support 210 by means of a horizontally disposed shaft 217, thus
enabling the lever to pivot in a vertical plane. To the upper end
of lever 214a is attached a horizontally disposed rotary shaft 215,
which rotatably holds a spool-like holder 226. Mounted in a
peripheral annular groove of holder 226 is a toroidally-shaped,
dirt removal body 222 made of a soft, plastically deformable body
which has a tacky surface to which particles of foreign matter on a
drill bit readily adhere when the body is pressed into contact with
the surface of a drill bit tip. Suitable materials for dir removal
body 222 include poly-isobutylene, various synthetic polymer clays
and the like. Rotary shaft 215 which supports dirt removal body 222
is coupled to a one-way clutch 216. Lever 214a is pivotably coupled
to mount 210 through a pivot shaft 217, which enables the lever to
pivot forward and backward in nodding-like motion, as indicated by
the double-ended arrow 223 in FIG. 10. Thus, when lever 214a
oscillates in the direction of arrow 223, in response to being
driven by motor 212 via wheel 213 and linkage 214, a turning force
is applied to the rotary shaft 215 through one-way clutch 216, thus
causing dirt removal body 222 to rotate in unison with rotary shaft
215.
[0068] FIGS. 11-13 illustrate an upper part of dirt removal
processing unit 42. As shown in FIGS. 11-13, the upper part of dirt
removal processing unit 42 includes toroidally-shaped cleaning body
222 mounted on a spool 226 rotatably held on a shaft 215 disposed
between parallel vertically disposed side plates 215a and 215b. As
shown in FIG. 11, a pair of laterally spaced apart right and left
generally cylindrical column-shaped upper side face dressing
rollers 224a for reforming and reshaping cleaning body 222 are
rotatably mounted on opposite sides of cleaning body 222. Side face
dressing rollers 224a have vertically disposed axles, and
vertically disposed inner cylindrical surfaces which contact
opposite vertical faces of cleaning body 222.
[0069] As may be seen best by referring to FIGS. 12 and 13, the
upper part of dirt removal processing unit 42 includes a pair of
vertically spaced apart and aligned, circumferential face dressing
rollers 225. Circumferential face dressing rollers 225 are
rotatably mounted to plates 215a and 215b on parallel, horizontally
disposed, vertically opposed axles, and each has formed in the
outer circumferential surface thereof an arcuately curved groove,
which is almost as wide as the roller, and which is adapted to
conformally receive the outer circumferential surface of cleaning
body 222, as shown in FIG. 13. As shown in FIGS. 11 and 13, the
upper part of dirt removal processing unit 42 also includes a pair
of laterally spaced apart, right and left, lower side face dressing
rollers 224b which are similar in construction and function to
upper side face dressing rollers 224a. However, lower rollers 224b
have horizontally disposed axles, and are located on the rear side
of cleaning body 222 rather than the upper side. The function of
the above-described rollers is to repetitively reform and
surface-dress toroidally-shaped dirt removal body 222, after each
pressing of the body against a tip of a drill bit 26 to remove dirt
from the tip. Rotation of dirt removal body 222 occurs as a result
of the cyclical nodding motion of arm 214a, as described above, and
the face dressing rollers are rotated by contact with rotating
lateral and circumferential surfaces, respectively, of the dirt
removal body. The face dressing rollers are preferably made of a
silicone-type material which does not adhere readily to the
material from which dirt removal body 222 is made. Dirt removal
body 222 is preferably made from a clay-like plastic material, such
as poly-isobutylene, polymer clays, and the like.
[0070] Inspection processing unit 44 of apparatus 20 is
substantially similar in construction and function to tip position
set up processing unit 38 shown in FIGS. 6 and 7 and described
above. Thus, inspection processing unit 44 also utilizes a tip
surface imaging system which displays an image of a drill bit 26 on
the monitor screen of a personal computer. Both visual observation
and pattern recognition software are used to identify any
non-conforming drill bit 26 which has been re-pointed at processing
unit station 40, and subsequently cleaned at post-grind dirt
removal station 42. As explained above, cleaning each bit 26 at
pre-grind dirt removal station 46 reduces the probability of
non-recognition of drill bit features at tip position set up
processing unit station 38, because of the removal of potentially
feature-obscuring dirt from the bit.
[0071] As previously explained, a pre-grind dirt removal station 46
is located adjacent to loading unit 36, and cleans each drill bit
26 prior to the bit being loaded off to processing unit 21 from
loading unit 36. Thus, arranged in a circle around base plate 37 of
loading unit 36 are the aforementioned pre-grind dirt removal
processing unit 46, a reject or defective discharge container 48, a
ring adjustment unit 50, and a input/output section 52. At both the
defectives discharge container 48 and the input/output section 52,
there is an input/output gate operated by a conveyor not shown in
the figures, the conveyer being arranged to transport a plurality
of drill bits in trays.
[0072] The structure and function of ring adjustment unit 50 may be
best understood by referring to FIGS. 14-16. A primary purpose of
ring adjustment unit 50 is to adjust the longitudinal position of a
collar ring 240a on a drill bit 26, which may have been altered
during the processing of the bit by processing uni 21.
[0073] As shown in FIG. 15, ring adjustment unit 50 includes a base
254 which protrudes obliquely from an attachment mount plate 256,
which is bolted to a fixed support structure (not shown). A motor
242 is attached to base 254. Attached coaxially to the shaft of the
motor is a coupling 241, which has protruding axially therefrom a
screw 252 which has attached to outer end thereof an enlarged
diameter, cylindrically-shaped support block 245 which fits within
the bore of a pressure compartment 244. Support block 245 has a
flat circular outer or upper face for contacting the butt end of
the shank of drill bit 26. Pressure compartment 244 contains a
drill receptacle 246 which has a coaxial cavity adapted to receive
a drill bit 26 fitted with a collar ring 240. Drill bit 26 is
supported by inserting the bit into the cavity of drill receptacle
246. A lever 247 is attached to front or upper sides of drill bit
receptacle 246. Radially aligned with tip side of drill bit 26 is a
detection compartment 250 that has a sensor 248 (see FIG. 16) which
faces opposite to pressure compartment 244. Detection compartment
250 is longitudinally movable by lever 247.
[0074] When motor 242 is driven, pressure compartment 244 moves
downwardly (FIG. 14) because of rotation of screw 252. When the
inner side of the front perforated end wall of pressure compartment
244 comes into contact with the front surface of collar ring 240,
the pressure compartment and collar ring move downwardly in unison
with respect to the drill bit shank, thereby adjusting the
longitudinal position of the collar on the shank. When collar ring
240 contacts lever 247, lever 247 moves in unison with the collar
ring, and detection compartment 250 moves in unison with the lever.
Movement of pressure compartment 244 is stopped when sensor 248
attached to detection compartment 250 detects the tip of drill bit
26. In this implementation, the distance between the detection
position of the tip of drill bit 26 and front surface of collar
ring 240 in pressure compartment 240 is set as the standard
distance of collar ring 240 from the tip of drill bit 26. After a
collar 240 has been pushed rearwards on the shank of a drill bit 26
to this preset distance, motor 242 is powered in a reverse
direction, therefore enabling detection compartment 250 to return
to its initial position by a spring mechanism not shown in the
figures.
[0075] FIG. 17 is a flow chart illustrating the workflow in
processing drill bits 26 using apparatus 20, beginning with step
(S100). First, as shown in FIGS. 1 and 5, a drill bit 26 is
supplied to loading unit 36, by conveying a tray loaded with a
quantity of individual drill bits 26, to input/output section 52,
by means of an external air chuck and air cylinder (not shown).
Drill bits 26 which is held in a upright vertical position within a
container, is tilted 45 degrees towards an air chuck 155, the
right-hand air chuck in FIGS. 5, by the action of an air cylinder
(not shown) of input/output section 52. At the same time, shaft 140
of loading unit 36 is elevated by a control unit not shown in the
figures. Elevation of shaft 140 raises spool 152 attached to the
upper end of the shaft to be elevated. This motion causes inner arm
154a of right-hand arm mechanism 154 to be raised, and outer arm
154b to be lowered, thus lowering air chuck 155 from a horizontal
orientation to a 45-degree downwardly inclined orientation. A
vacuum source connected to port 156 on air chuck 155 as described
above is then energized, producing suction pressure at port 156
which to thereby grip a drill bit 26 in the air chuck. Shaft 140 is
then lowered, causing outer arm 154b to rotate upwardly to a
horizontal position, as shown in phantom on the left side of FIG.
5. Shaft 140 and rotary pedestal 148 are then rotated a fixed
angular increment (72 degrees clockwise in a five-station example
of the present embodiment), by the driving gear 146, thus air chuck
155 and drill bit 26 of pre-grind dirt removal processing unit 46
(FIG. 1). Note that in this embodiment, loading unit 36 is made to
rotate only when shaft 140 is lowered, with drill bit 26 thus being
held in a horizontal orientation. After the five incremental
rotation of rotary pedestal 148, shaft 140 is again raised, causing
air chuck 155 to angle downwards at 45 degrees. Suction of air
chuck 155 is then stopped, thereby causing drill bit 26 to be moved
to a drill holder mechanism (not shown) of dirt removal processing
unit 46.
[0076] At pre-grind dirt removal processing unit 46, the tip of
drill bit 26 is made to touch dirt removal body 222, thus causing
dust, dirt, and other particles of foreign matter covering the tip
to adhere to the dirt removal body 222. (S102). After the dirt
removal process has been completed, drill bit 26 is picked up by
air chuck 155 in the manner described above, loading unit 36 is
rotated 72 degrees, and the air chuck 155 holding the cleaned drill
bit 26 is thus made to face opposite to a drill bit holder
mechanism 28 located on index plate 22 of processing unit 21. Drill
bit 26 is then transferred to drill bit holder 28 of processing
unit 21 from air chuck 155 of loading unit 36. (S104). At this
pickup and delivery or transfer location, shank pressure arm 126 of
holder unit 28 is pivoted away from the shank holder by a flat cam
(not shown), when air chuck 155 holding a drill bit 26 is axially
aligned with and adjacent to the shank holder portion of drill bit
holder unit 28. With drill bit 26 still held in air chuck 155, the
tip of the drill bit is positioned in edge receptacle 128 of drill
bit holder 28, and the shank of the drill bit is positioned in
contact with the front end of push rod 104. Vacuum to air chuck 155
is then removed thus enabling the drill bit from air chuck 155 to
move to drill bit holder 28. Then, index motor 64 is driven,
causing index plate 22 to rotate 72 degrees from the delivery or
hand-off position to a position adjacent to tip position set up
process unit 38. During this rotation, shank pressure arm 126 is
actuated by a flat cam (not shown), which causes shank idler
bearing 124 to press down on the shank of drill bit 26, thus
holding the bit in drill bit holder 28.
[0077] At tip portion set up process unit 38, the elevation of the
center of the core of drill bit 26 is adjusted, as well as the
axial position of the tip of the bit, and the phase angle of the
flutes (S106). The sequence of steps in the tip portion set up
process may be best understood by referring to FIG. 18. FIG. 18 is
a flow chart diagram showing the sequence of process steps in
adjusting the axial tip position, core elevation, and phase of
drill bit 26 with the apparatus of FIG. 20.
[0078] A first step in the tip set up process consists of centering
the core elevation of drill bit 26 at a temporary provisional
position, e.g., at the middle of the adjustment range of the
apparatus. (S200). This is done to enable subsequent more precise
adjustments of core elevation, axial position and phase angle.
During this temporary core center height adjustment step, the tip
of drill bit 26 is moved into the field of view of CCD camera 178
by moving tip portion support edge receptacle 128, using vertical
slider mechanism 128. Displacement at edge receptacle 128 is under
software to an initial predetermined nominal value which positions
the tip of drill bit 26 within the field of view of CCD camera 178.
(See FIGS. 6 and 7).
[0079] Next, horizontal slider motor 110 is energized and the axial
tip position of drill bit 26 is adjusted. As shown in FIG. 6, the
tip of drill bit 26 is moved until it is detected by tip portion
detection sensor 188 (S202). Movement of drill bit 26 is effected
by motion of horizontal slider mechanism 88 of drill bit holder 28.
Prior to initial movement of horizontal slider mechanism 88, lever
96 of horizontal slider mechanism had been moved by an air cylinder
(not shown) to thereby position horizontal slider plate 94 at its
radially innermost position, i.e., the right-most position in FIG.
3, thus causing the axial tip portion of drill bit 26 to be at its
lowest height. At this time, rack 112b and pin 114 of tip position
process unit 38 are also located at their radial innermost
positions. Thereafter, rack 112b moves radially outwards (to the
left in FIG. 3) in response to operation of horizontal slider drive
motor 110. This action causes pin 114 protruding upwardly from rack
112b to engage lever 96 protruding downwardly from slider plate 94,
pulling the slider radially outwards, i.e., to the left in FIG. 3,
which in turn causes drill bit 26 to ascend. Thus, when horizontal
slider plate 94 is moved radially outwards, follower plunger 100 is
raised, which in turn causes push rod 104 to move obliquely upwards
because of counterclockwise motion of link 108 about pivot pin 111,
which causes the upper end of link arm 108a to push against cap
107b at the rear end of push rod 104. Obliquely upward motion of
push rod 104 in turn pushes drill bit 26 axially forward, thus
advancing the tip of the drill bit obliquely forward and parallel
to the sides of receptacle 128.
[0080] Initial movement of drill bit 26 is limited to a movement
just sufficient to position the drill bit tip so that it may just
be detected in the field of view of position control sensor 188.
(S204). Position control sensor 188 then produces a detection
signal which is used to stop motor 110, causing forward axial
motion of the drill bit tip to cease. (S206). Then, in order to
prepare for rotation of index plate 22, horizontal slider drive
motor 110 is powered in a reverse direction, causing rack 112b and
pin 114 to return to their radially innermost, extreme right-hand,
starting positions.
[0081] Next, phase adjustment of drill bit 26 is performed using
the image of the tip surface of the drill bit photographed by CCD
camera 178. Referring again to FIG. 4, phase adjustment is
accomplished by powering phase adjustment motor 84, thus rotating
pinion gear 134, gearwheels 132, and rubber rollers 122, and
thereby rotating the shank of drill bit 26, pressed against rubber
rollers 122 by idler bearing 124. Phase motor 84 is powered until
an image of the drill bit tip photographed by CCD camera 178
indicates that flutes at the front cutting portion of the drill bit
are oriented approximately at a predetermined angle relative to a
fixed machine reference plane. Then, based upon images of the tip
photographed by CCD camera 178, the center (core elevation)
position and phase angle of drill bit 26 are readjusted (S210) to
predetermined numerical values under software control, in a
iterative sequence, a sufficient number of times until the bit
position is sufficiently optimized for the grinding end portion of
the bit to begin. (S212).
[0082] Index plate 22 of processing unit 21 is then rotated to
locate the optimally positioned drill bit 26 adjacent to drill bit
grinding processing station 40. (S108). Here, grindstones 190, 192
are moved and set obliquely to the drill bit 26 as the traverse
mechanism is actuated, thus grinding the bit as shown in FIG. 8.
After a side of the drill bit 26 has been ground, the phase of the
bit is rotated 180 degrees by powering phase motor 84. The second
side is then ground to complete the re-pointing operation.
[0083] Index plate 22 of processing unit 21 is again rotated to
locate the re-pointed drill bit 26 adjacent to post-grind dirt
removal process unit 42, which functions exactly the same as
pre-grind dirt removal process unit 46. Thus, synchronous motor 212
is powered, causing ring 213 to rotate eccentrically and thereby
oscillate the link mechanism 214 connected to the ring.
Accordingly, pivoting lever 214a, which is coupled to the link
mechanism 214, rises and falls as shown by the arrow mark 223 in
FIG. 10; during this operation, the tip of the drill bit 26 is
inserted into dirt removal body 222 positioned at the upper end of
pivot lever 214. When thus inserted, foreign matter adhered to the
drill bit is transferred to dirt removal body 222. Pressing dirt
removal body 222 against the tip of drill bit 26 is effected by
pivoting lever 214 downwardly towards the drill bit tip, i.e.,
counterclockwise as shown in FIG. 10. As dirt removal body 222
moves downwardly to impact the tip of drill bit 26, dirt removal
body 222 is held fixed without rotation. After the tip of drill bit
26 has pierced dirt removal body 222, lever 214a moves clockwise,
retracting dirt removal body from the drill bit tip. During this
motion, dirt removal body 222 is rotated as a result of the one-way
clutch, thus causing relative motion between the dirt removal body
and face dressing rollers 224 and 225, reforming the dirt removal
body to its initial unpierced, toroidal shape.
[0084] Index plate 22 of process unit 21 is again rotated to locate
re-pointed and cleaned drill bit 26 adjacent to inspection
processing unit 44, to determine whether the drill bit meets
predetermined quality criteria. (S112). Inspection is performed
using electro optical components substantially similar in
construction and function to those of tip position set up
processing unit 38. However, in the case of a drill bit 26
transported to inspection process station 44, the axial position,
center (core elevation) and phase of the drill bit have already
been adjusted, so that the drill bit point is prefocused and within
the field of view of the CCD camera at the inspection station, thus
allowing photographs to be quickly made, and at least two
parameters of the re-pointed drill bit compared with predetermined
criteria, to thereby determine whether the re-pointed drill bit is
acceptable or defective.
[0085] Index plate 22 of process unit 21 is again rotated to
position pre-pointed, cleaned, and inspected drill bit 26 at a
location adjacent to loading unit 36. Here, shank idler bearing 124
is raised, releasing drill bit 26 from holder unit 28, and air
chuck 155 of a transfer arm mechanism 154 actuated to pick up the
drill bit and thus transfer it to loading unit 36.
[0086] The results of the quality assurance inspections made on
each drill bit 26 at inspection processing station 44 are stored in
electronic memory (not shown). Therefore, when incremental rotation
of rotary pedestal 38 of loading 36 has positioned an air chuck 155
holding a defective drill bit 26 adjacent to defectives discharge
container 48, that arm mechanism 154 supporting air chuck 155 is
automatically actuated to interrupt vacuum to the air chuck and
thereby deposit the defective drill bit in the defectives
container.
[0087] Drill bits 26 which have passed inspection at inspection
station 44 are transported on rotary pedestal 38 of loading unit 36
to a location adjacent to ring adjustment unit 50, where a collar
ring 240 press fitted onto the shank of the bit is adjusted in the
manner described in detail above. Rotating pedestal 38 is then
rotated to position a re-pointed and inspected drill bit 26 fitted
with a properly adjusted collar ring 240 adjacent to input/output
section 152, where an arm mechanism 154 holding the bit is actuated
to transfer the bit to a transport container.
[0088] The functions of the drill bit pointing and dust removal
apparatus according to the present invention and described above
are preferably controlled by a transport control unit comprising a
microprocessor or general purpose computer such as a personal
computer (PC), as will be recognized by and well within the
capabilities of one skilled in the art. In a preferred mode of
operation, processing unit 21 and circular pedestal 148 are
periodically and non-simultaneously rotated to move drill bits
between various stations and paused for relatively longer periods
to allow sufficient time for processing and loading operations at
the various stations to be simultaneously performed.
* * * * *